404389709 has 2 divisors, whose sum is σ = 404389710. Its totient is φ = 404389708.

The previous prime is 404389697. The next prime is 404389751. The reversal of 404389709 is 907983404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 353552809 + 50836900 = 18803^2 + 7130^2 .

It is a cyclic number.

It is not a de Polignac number, because 404389709 - 2²⁴ = 387612493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 404389709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404389789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202194854 + 202194855.

It is an arithmetic number, because the mean of its divisors is an integer number (202194855).

Almost surely, 2^404389709 is an apocalyptic number.

It is an amenable number.

404389709 is a deficient number, since it is larger than the sum of its proper divisors (1).

404389709 is an equidigital number, since it uses as much as digits as its factorization.

404389709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 404389709 is about 20109.4432792159. The cubic root of 404389709 is about 739.4918041072.

The spelling of 404389709 in words is "four hundred four million, three hundred eighty-nine thousand, seven hundred nine".